Clinton County is a county located in the U.S. state of Missouri. As of a 2017 U.S. Census, the county had a population of 20,743.[1] Its county seat is Plattsburg.[2] The county was organized January 2, 1833 and named for Governor DeWitt Clinton of New York.[3][4] The county seat of Plattsburg derives its name from a town of a similar name that is the county seat of Clinton County, New York, which was also named for the Governor.

Clinton County is part of the Kansas City, MO-KS Metropolitan Statistical Area.